Search

Modification of polyacrylonitrile fiber by ethylenediamine in aqueous solution and the vapor phase was investigated. The optimum process conditions were determined. The process was found to be significantly enhanced if the gaseous amine was used rather than its aqueous solution. FTIR spectra confirmed the structure of polymer fiber produced under these conditions. [ABSTRACT FROM AUTHOR]

The effect of the precipitation-bath concentration on the viscoelastic properties of wet-spun polyacrylonitrile fiber was studied. The polymer system to be deformed was modeled structurally as a network of intermolecular linkages that consisted of viscous and elastic nodes and could be used to explain many physical phenomena occurring during the deformation, in particular, the known phenomenon of forming voids and vacuoles in the spun fiber. It was shown that the jet-fiber during spinning into mild baths transitioned sequentially from the viscoelastic state, initiating a pathway that formed a viscous (Newtonian) state at its end. The effect of the precipitant composition on the structure-fixation length and time for a jet in the viscous and viscoelastic states was examined. [ABSTRACT FROM AUTHOR]

This paper presents the developed probabilistic spatial model fragments of the structure of polyacrylonitrile fiber, the monomerization composition (condensing components of the polymer matrix), and 'Polikon K' - 'Polikon K' material. The dynamic contact angle of the investigated material was experimentally determined, and the work of adhesion (1.154 mJ/m) and wetting (73.855 mJ/m) of the surface material was calculated. The model of the structure of the 'Polikon K' material indicates the most likely point of interaction of copolymer polyacrylic fiber with reactive CH- groups of the polymer matrix, namely, the interaction with the C≡N group, by breaking one bond and forming a methylene bridge. The size of the unit cell of the model was estimated: 10.6 × 10.3 × 9.7 Å. The dependence of the torsion angle near the methylene bridge on the concentration of water molecules was investigated. [ABSTRACT FROM AUTHOR]

We consider the thermodynamics of dyeing of polyacrylonitrile fiber by cationic dyes. The dye bath - fiber system is divided into three layers: the dye solution in the dye bath, the interphase layer, and the amorphous regions of the fiber. [ABSTRACT FROM AUTHOR]

The preparation of acrylonitrile, methylacrylate, and 2-acrylamido-2-methylpropanesulfonic acid terpolymer fiber and its dyeing by anionic dyes were examined. The stability of the dye in modified polyacrylonitrile fiber was studied. It was shown that the modified fiber had bactericidal properties. The fiber physicomechanical properties changed insignificantly as a result of the modification and coloring. [ABSTRACT FROM AUTHOR]

The effect of treatment with various chemical modifiers on the physicomechanical properties of polyacrylonitrile (PAN) fibers was studied. The structures of the finished reinforcing systems were analyzed. The hardening kinetics of an epoxide binder in the presence of the modified fibrous systems were studied. It was found that modification of PAN filament improved the mechanical properties of epoxide composites based on it. [ABSTRACT FROM AUTHOR]

Theoretical calculations are performed for three compositions of Kamvol yarn made with the use of polyacrylonitrile fibers. The instruments, equipment, and method used to determine the stiffness characteristics of the fibers and yarn are described, and results are presented from experimental determination and calculation of the strength of the individual fibers and the three compositions of twisted yarn. [ABSTRACT FROM AUTHOR]